The present invention, in general, relates to lighting fixtures and, more particularly, to an explosion-proof fluorescent light fixture for use in hazardous environments.
Already well known in the art are explosion-proof-type lighting fixtures which use one or a plurality of parallel fluorescent lamps and which fixtures, typically, are utilized in hazardous areas and harsh surroundings as, for example, areas having a high gaseous atmosphere such as oil and gas refineries, and are further wisely used on board off-shore drilling rigs, on-shore drilling rigs, on oil-and-gas transport tankers, mines and, in short, in every place where, to one degree or another, flammable and explosive fumes are always present.
It will be appreciated that, for example, in places with high gaseous atmospheres a spark emanating from an insufficiently shielded lamp fixture could set off a considerable explosion that could damage both men and surroundings. Such a spark could be the result of an excessively high pressure build-up within the lamp structure, a wiring deficiency or a short, or the like.
To avoid these type of occurrences, presentday fluorescent lamp fixtures are made substantially explosion-proof. For instance, the end caps of the end connectors which support the lamps and their associated globes, are hermetically sealed in position by threaded sealing elements. In another instance, the globes which protectively surround and enclose the lamps, are sealably seated and fixedly positioned in the end connectors. In case of an excessive build-up of pressure, the latter is released by way of its weakest creeping route, the threaded seals. In structures where the globe ends are rested against inner connector seals, then such seals form a prime route for the release of the excessive pressure. If breakage of the globe should occur, replacement is extremely time consuming, usually causing temporary secession of drilling or mining operations.
Typically, in conventional fluorescent light fixtures, the globes are integrally formed with their associated end pieces or connectors and cannot be individually replaced. In some instances and depending upon the construction of the fixture, the latter has to be totally dismantled in order to repair or replace the globes. In other instances, the entire lamp fixture has to be discarded.
Breakage of a globe is a rather frequent occurrence. Sometimes it is a worker who accidentally hits and breaks the globe, other times it is an object that strikes the globe and demolishes its structure. In all instances, prior art lamp fixtures of the type under discussion employ globes that cannot easily be replaced, if replaceable at all. As a matter of rule, it takes from three to four hours to replace a whole fixture, which in terms of economy is extremely costly, this aside from the inconvenience that is caused by such an event.
Consequently, there is a great need to improve such lighting equipment and develop an explosion-proof fluorescent light fixture which enables the light unit to remain functional and which, in case of globe breakage, enables a easy, effective and, above all, an extremely fast manner of exchanging the damaged component.